Various different types of electro-optic display are known, including liquid crystal displays, electrophoretic displays, electrochromic displays, etc. A recently developed type of electro-optic display is an electrowetting display, as described amongst others in international patent applications WO 2003/071346 and WO 2005/098797.
For explanatory purposes, a prior art drive circuitry arrangement and its driving scheme is illustrated in FIGS. 7, 8 and 9. Referring to FIG. 7, in the prior art arrangement, a common voltage signal is held at a voltage level Vcom, whilst an actuating voltage signal Vout is modulated by selectively actuating switches S1 and S2—this may for example be carried out according to the switching scheme illustrated in FIG. 9. This results in the output waveform shown in FIG. 8. A disadvantage of the switching scheme shown is that the voltage step required, and the associated rate of change of voltage, is relatively high.
It would be desirable to provide an improved method of driving an electro-optic apparatus. In particular, but not exclusively, it would be desirable to provide an improved method of driving an electrowetting display.